Transceiver antenna system for platooning

ABSTRACT

A system with one or more transceiver antenna assemblies for installation in vehicle side-view mirrors to enable communication with nearby vehicles. Each transceiver antenna assembly may have one or two antenna arrays implemented on a single printed circuit board, protected by an antenna housing used to mount the transceiver antenna inside the mirror assembly. Each antenna array in a dual-channel transceiver antenna may transmit and receive data over one of two DSRC channels. One channel may be used to transmit and receive vehicle data only and the other channel may be used to transmit and receive both vehicle data and audio/video (A/V) data. Each antenna array is connected to a radio in the vehicle that processes received signals and prepares signals for transmission. Such a transceiver antenna system may be especially useful for communication in truck platooning.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Application No. 62/509,663, filed May 22, 2017 entitled“Transceiver Antenna for Vehicle Side Mirrors”, hereby incorporated byreference in its entirety, and is related to an Application entitled“Transceiver Antenna for Vehicle Side Mirrors” filed concurrently withthe present Application and hereby incorporated by reference in itsentirety.

FIELD OF THE INVENTION

The embodiments disclosed herein relate to radio frequency (RF)transceivers for communication between vehicles, and in someembodiments, RF transceivers that may be particularly useful for truckswhen platooning.

BACKGROUND

In certain situations, it is desirable that vehicles in motion have theability to reliably exchange information. Various standards have beenestablished for such vehicle-to-vehicle (V2V) communication via wirelessnetworks. One common set of communication channels is known as dedicatedshort range communication (DSRC), implementing the IEEE 802.11p standardfor wireless access in vehicle environments (WAVE). In the UnitedStates, 75 MHz of spectrum in the 5.9 GHz band (5.850-5.925 GHz) hasbeen allocated for use in intelligent transportation systems. Othercountries may allocate different portions of the RF spectrum for DSRCcommunications.

Inter-vehicle communication using DSRC may be especially useful when twoor more large trucks (such as semis) wish to achieve certainefficiencies by platooning to reduce drag and save on fuel costs. Shortto medium range communication in such a situation may be used totransmit control, status, situational, and/or audio and video databetween the vehicles. Parallel communication on multiple channelsbetween vehicles may be useful to provide all the data and informationneeded to maintain safe and effective platooning. However, this type ofcommunication typically requires a direct line of sight between antennasof the two vehicles for the data to be transmitted properly.

Traditional antennas are insufficient for establishing reliablemulti-channel short to medium range communication connections betweenmoving trucks. Low gain or no gain antennas have been shown to beinappropriate for vehicle-to-vehicle communication because they oftenincur significant ground interference. However, off-the-shelf high-gainantennas appropriate for mounting on a vehicle provide communicationover only a single channel and are rather bulky and unwieldy. Forexample, short and medium range communication antennas for 5.8-5.9 GHzbands, such as the ECOS product line by Mobile Mark, Inc., provide onlya single channel. Therefore, in order to achieve multiple simultaneouschannels of communication, multiple antennas may be needed at eachinstallation location on each vehicle.

As will be explained in more detail below, the desirable installationlocation for antennas used for communication between large trucks is onor within the trucks' side-view mirrors. Consequently, establishingmultiple channels of communication at each mirror can require four ormore off-the-shelf antennas. Additionally, the ECOS antenna is ratherbulky and expensive. When such off-the-shelf DSRC antennas are installedon the side mirror of a large truck (e.g. attached to the perimeter ofthe side mirror and protruding above the mirror), there is a high riskthat the antenna will become detached from the mirror while the truck isin motion, for example when the truck is maneuvering through tightspaces or locations with a lot of vegetation.

It is therefore apparent that a need exists for a small, reliableantenna appropriate for multi-channel communication between large,moving vehicles.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other aspects of various embodiments of the presentinvention will be apparent through examination of the following detaileddescription in conjunction with the accompanying drawing figures inwhich similar reference numbers are used to indicate functionallysimilar elements.

The illustrations in the Drawings disclosed in this Application aremeant to illustrate the function of various embodiments, and aretypically not shown to scale. Any specific details regarding specificdimensions of various elements and any relationships between them shouldbe provided in descriptions in the text of the Specification and theattached Claims.

FIG. 1 is a top-view diagram that illustrates an exemplary pair ofvehicles that may require vehicle-to-vehicle communication.

FIG. 2 illustrates an exemplary dual-channel antenna according to anembodiment.

FIG. 3 illustrates an exemplary antenna according to an embodiment.

FIG. 4 illustrates an exemplary antenna assembly for a dual-channelantenna according to an embodiment.

FIG. 5 illustrates an exemplary antenna housing for a dual-channelaccording to an embodiment.

FIG. 6A illustrates an exemplary dual-channel antenna and assemblyaccording to an embodiment.

FIG. 6B illustrates an exemplary dual-channel antenna and assemblyaccording to an embodiment.

FIG. 7 illustrates an exemplary dual-channel antenna assembly in aside-view mirror of a vehicle according to an embodiment.

FIG. 8A illustrates an exemplary antenna assembly mounted inside aside-view mirror assembly for a truck according to an embodiment.

FIG. 8B illustrates a top-view of the side view mirror assembly of FIG.8A.

FIG. 9A illustrates an exemplary antenna assembly mounted inside aside-view camera housing according to an embodiment.

FIG. 9B illustrates an exemplary antenna assembly mounted outside aside-view camera housing according to an embodiment.

DETAILED DESCRIPTION

The present invention relates to a transceiver antenna to be installedin a vehicle side-view mirror to enable short and medium rangecommunication with nearby vehicles. The transceiver antenna is designedto fit within the side view mirror of a vehicle, preventing additionalwind resistance. In some embodiments, the transceiver is designed totransmit and receive radio signals over DSRC channel. According to anembodiment, each transceiver antenna may include a single antenna array.According to an embodiment, each transceiver antenna may include twoantenna arrays implemented on a single printed circuit board, orientedsuch that each antenna array is in the null space or region of the otherto minimize interference and cross-talk (a dual-channel antenna). In anembodiment, the transceiver antenna may be encased in an antenna housingconfigured to safely mount the transceiver antenna in a side mirror of avehicle while minimizing interference and protecting the transceiverantenna.

Each antenna array in the transceiver antenna will transmit and receivedata over an assigned radio channel. In the case of the dual-channelantenna, each antenna array will transmit and receive data over one oftwo assigned channels. One channel may be used to transmit and receivevehicle data, whereas the other channel may be used to transmit andreceive both vehicle data and audio and/or video (A/V) data. Eachantenna array is connected to a radio within the vehicle that processesreceived signals and prepares signals for transmission.

As noted above, the type of desired communication between vehiclestypically requires a direct line-of-sight between antennas for the datato be transmitted properly. However, this can be problematic fortractor-trailer semis. Because a large truck with a tractor-trailer(e.g. a semi) may have a trailer that is taller than the cab, andbecause the truck and trailer are independent and therefore canarticulate, it is difficult to maintain short range line-of-sightcommunication.

FIG. 1 illustrates an exemplary pair of trucks that may requiretruck-to-truck (or vehicle-to-vehicle (V2V)) communication. In FIG. 1,the lead truck 101 has multiple options for antenna locations. Threeexemplary antenna locations 110, 111, 112 are shown. One of theillustrated exemplary antenna locations 111 is in the middle of thetruck cab. However, as can be seen in FIG. 1, the middle antenna 111 maynot have a direct line of sight with the following truck 150, forexample, because of the trailer height. Any antenna used for short tomedium range communication between two tractor-trailer trucks cannottherefore rely on an antenna that is placed on or within the body of thecab. Placing an antenna on the trailer would also be problematic as thetrailer and the cab are often disconnected, and the trailers are oftenexchanged between different truck cabs. Either the antenna would have tobe disconnected from one trailer and attached to the new trailer, or anew antenna permanently attached to the new trailer would have to beconnected to the radio in the cab whenever the trailer is switched on atruck.

However, placing an antenna at locations 110, 112 in each side mirror ofthe cab increases the likelihood that the lead truck 101 will have atleast one side mirror (and therefore one antenna) in direct line ofsight with at least one side mirror (and therefore one antenna) of thefollowing truck 150. One antenna, for example the antenna in the rightside location 112, may not be in direct line of sight with any antennaon the following truck 150 when the lead truck 101 is turning left.However, if the antenna in the right-side location 112 is blocked, theantenna in the left-side location 110 should still have a direct line ofsight to one of the antenna locations 151, 152 on the following truck150. Therefore, regardless of the articulation of the cab and trailer orthe height of the trailer, with an antenna in each side mirror location,one of the antennas should always be capable of transmitting a short tomedium range signal to at least one of two antennas mounted in the sidemirrors of a following truck.

Once communication is established between two vehicles, using DSRC forexample, the antenna may transmit and receive data on any DSRC dedicatedchannel. According to an embodiment, the antenna may be tuned totransmit and receive data via any one of seven dedicated channels withinthe DSRC band (one channel being a control channel, and six channelsbeing service channels) or may dynamically hop frequencies as requiredto ensure the data is correctly transmitted and received.

The types of data that may be transmitted between trucks include vehicledata and audio/video (A/V) data.

According to an embodiment, the vehicle data may include informationcritical for safety, as well as control data for the vehicle. Suchsafety-critical information may include acceleration information,braking information, system activation/deactivation, system faults,range or relative speed, or other data streams related to vehiclecontrol. The vehicle data may also include the vehicle's recent GPScoordinates, its present estimated velocity, an estimate of the relativevelocity of the vehicles, and other navigation and orientationinformation as may be needed for safe platooning.

The vehicle data may additionally include one or more signals that donot directly carry information encoded as a bitstream, but may be usedto allow information about the vehicle, such as its relative speed andrelative distance, to be determined. For example, the vehicle data maycomprise a steady signal at a predetermined RF frequency broadcast byone vehicle, from which a second vehicle may infer information about thevehicles' relative speed from the Doppler shift of the received signal.

In an embodiment, the vehicle data may be transmitted on one channelwhile the A/V data is transmitted on another channel. In an embodiment,the vehicle data may be transmitted on two channels while the A/V datais transmitted on only one channel. This redundant approach to thevehicle data provides a higher likelihood of successful vehicle datatransmission between trucks (the A/V data having lower priority andtherefore being transmitted with only one channel).

According to an embodiment, the audio/video (A/V) data may include avideo stream from one or more cameras placed in or around the truck,voice communication that may be exchanged between drivers of multipletrucks, or other audio or video data as may be made available. It mayinclude only audio data, or only video data, or some combination ofaudio and video data. It may include live streams of data, recordedinformation, or A/V data with a time delay in transmission.

As described above, transceiver antennas are preferred at eachinstallation location (in some embodiments, in the truck side mirror ormirrors). A single dual-channel antenna may be utilized to minimize thenumber and size of components installed in each side mirror. FIG. 2illustrates an exemplary dual-channel antenna 200 according to anembodiment, in which two antenna arrays 210, 250 are created on a singlestandard printed circuit board (PCB) 201. The dual-channel antenna 200is designed to be mounted in a vehicle side-mirror and carry both signaltransmission and signal reception. The PCB may be fabricated from FR-4or other such flexible, epoxy/glass based substrates, while the antennaarrays may be fabricated from a metal such as copper coated onto the PCBsubstrate and subsequently patterned.

According to an embodiment, the PCB 201 may be have a thickness ofapproximately 30 mils (or approximately 0.76 mm). According to anembodiment, the antenna arrays 210, 250 fabricated as copper traces onthe PCB may have a trace width between 12 and 35 mils (or approximatelybetween 0.30 and 0.89 mm) and a thickness of 3.5 mils (or approximately89 micrometers). As illustrated, the two antenna arrays 210, 250 arecollinearly oriented, i.e. aligned to have the same axis of orientation.This means that each antenna array may be in the null region of theother antenna array, which can reduce or minimize interference andcrosstalk between the antenna arrays. In an embodiment, the antenna mayhave two antenna arrays with respective axes aligned in parallel, butwith an offset, i.e. not sharing the same axis. This may provide otheradvantages when placed within certain mirror housings, if crosstalk canbe otherwise minimized.

Each antenna array may handle both signal transmission and signalreception. Each antenna array is fed from a separate radio through a via203, 253 and a radio connector 204, 254 respectively. The radioconnectors 204, 254 may be soldered to the respective antenna array toform the appropriate connection. The vias 203, 253 through the PCB 201may provide the appropriate connection for each respective radioconnector 204, 254. A ground plane 202 on the far side of the PCB 201 inthe region around the connectors may be provided in some embodiments.

According to an embodiment, the vias for the radio connectors may beclosely spaced. According to another embodiment, the vias may be spacedas far apart as possible, based on the length of the dual-channelantenna assembly. For example, if the antenna assembly is limited to beapproximately 40 cm in length to fit within a standard truck sidemirror, and the PCB is therefore limited to be approximately 36 cm inlength to fit within an antenna housing having a suitable air gap, two6-element DSRC antenna arrays may both fit on the PCB while leaving thedistance between the radio connectors to be approximately 98 mm. Otherembodiments having shorter antenna arrays may allow greater separationof the connectors. In some embodiments, connections may be made to theradio by using a coaxial connector, and the coaxial center wire may beconnected by soldering it to the radio connector 204.

As illustrated, each antenna array 210, 250 has a number of antennaarray elements. The lower antenna array 250 is the mirror image of theupper antenna array 210, and so the further description for the upperantenna array 210 may also apply in mirror image to the lower antennaarray 250. The upper antenna array 210 has antenna has six (6) arrayelements 211 a, 211 b, 212, . . . , 216, each separated by one of five(5) phase delay sections 221, . . . , 225. Each array element adds gainto the received or transmitted signal. The array elements may befabricated to have a wider trace than the delay lines, and, in anembodiment, the array elements are fabricated may have a trace widthtwice as wide as the delay lines. As shown in FIG. 2, an exemplaryantenna array has 6 elements with 5 phase shifting delay lines betweenthem; however, an antenna array with as few as 2 and as many as 12 arrayelements could also be implemented. The additional array elements inantenna arrays with more array elements, however, may only providemarginal gain after the loss of transmission through the other antennaarray elements is considered.

Each array element in an antenna array may be the same length, or theymay have different lengths. For example, for the upper antenna array 210as illustrated in FIG. 2, starting at the element closest to the radioconnector (Array Element 1 a) and progressing outward, each subsequentarray element may be a slightly longer than the element before it. In anembodiment, each array element will be 5% longer than the previous arrayelement. This gradual lengthening may improve performance. According toan embodiment, it may be desirable to vary the lengths of the elementsin the array. Exemplary array element lengths in mm for several designsof a 6-element array tuned for DSRC RF communication are shown in TableI.

TABLE I Exemplary Antenna Array Element lengths for 5 different6-element designs. Array Array Array Array Array Array Length ElementElement Element Element Element Element (mm) 1a 1b 2 3 4 5 6 Design 18.0 8.0 20.5 20.5 20.5 20.5 20.5 Design 2 7.7 7.7 18.6 19.5 20.3 20.320.2 Design 3 8.0 8.0 20.5 21.3 22.2 23.0 23.9 Design 4 8.0 8.0 20.519.7 19.0 18.3 17.6 Design 5 7.7 7.7 18.6 19.5 20.5 21.5 22.6

The nominal trace width for all array elements is 0.8 mm, except forarray element 1, which is split into two sections, array element 1 a(211 a) and array element 1 b (211 b). Of these two segments, arrayelement 1 a (211 a) (closest to the radio connector) may overlapadditional metal structures 205 fabricated on the backside of the PCB201. The metal structures 205 may have “outriggers” (semi-attachedwire-like structures, as illustrated) or other shapes, such as the metalground plane 202, that together act as a balun at the junction betweenthe radio connector 204 and the 50Ω, microstrip on the front side of thePCB 201.

The backside metal structures 205 help ensure that the cable connectionitself does not serve as part of the antenna line. In some embodiments,the backside metal structures 205 may overlap exactly half of the lengthof array element 1, splitting element 1 into two elements 211 a, 211 bof equal length. In some embodiments, the trace width of array element 1a 211 a over the backside metal structures 205 will be 0.34 mm, whilethe trace width of array element 1 b 211 b will be 0.8 mm. Asillustrated, the radio connector 204 may also be fabricated from thecopper material deposited on the PCB 201 to form the antenna array, butmay typically be wider, having a width, for example, of 1.4 mm.

Similarly, the delay lines or phasing sections in each array may haveconstant or variable lengths. Exemplary phasing section length optionsfor the 5 phasing sections positioned between the antenna elements inthe 6-element arrays of Table I (designed with Phase Delay 1 positionedbetween Antenna Elements 1 and 2, etc.) are shown in Table II (shown inmm, assuming a trace width of 0.4 mm). It should be noted that theserepresent total trace length for the phase delay section, as the pathfollows a non-linear, generally serpentine path, as illustrated in FIG.2. The actual linear physical length of the section will be shorter,often less than 10 mm.

TABLE II Exemplary Phase Delay lengths for 5 different 6-elementdesigns. Length Phase Phase Phase Phase Phase (mm) Delay 1 Delay 2 Delay3 Delay 4 Delay 5 Design 1 20.5 20.5 20.5 20.5 20.5 Design 2 16.7 16.717.1 16.7 16.3 Design 3 20.5 20.9 21.3 21.7 22.1 Design 4 20.5 20.1 19.719.3 18.9 Design 5 16.7 17.5 18.4 19.3 20.3

According to an embodiment, a single antenna array may be utilized. FIG.3 illustrates an exemplary antenna 300 according to an embodiment. Asshown in FIG. 3, a single antenna array 310 is created on a standardprinted circuit board (PCB) 301. The single antenna array 310 is fedfrom a radio through a via 303 and a radio connector 304. Connectionsmay be made to the radio by using a coaxial connector, and the coaxialcenter wire may be connected by soldering it to the radio connector 304.The single antenna array 310 is designed to be mounted in a vehicleside-mirror and handles both signal transmission and signal reception.

As with the dual-channel antenna described above, the single antennaarray 310 has a number of antenna elements 311 a, 311 b, 312, . . . ,316, each separated by a delay line 321, . . . , 325 that marks a phaseshifting section. Each array element adds gain to the received ortransmitted signal. The lengths of the antenna array elements 311 a, 311b, 312, . . . , 316 may correspond to the exemplary lengths for antennaarray elements 211 a, 211 b, 212, . . . 216 previously shown in Table I.Likewise, the path lengths of the phase delay sections 321, . . . , 315may correspond to the phase delay lengths 221, . . . , 225 previouslyshown in Table II. As shown in FIG. 3, an exemplary antenna array has 6elements, however, an antenna array with as few as 3 or as many as 12elements could also be implemented. As described above, each arrayelement may be the same length, or may have different lengths.

As shown in FIG. 3, and as described for the embodiment of FIG. 2, anantenna array may include backside metal structures 305 at the junctionof the antenna array and the unbalanced connector from the radio. Insome embodiments, this combination may serve as a balun at the junctionof the antenna array and the radio connector. According to anembodiment, the backside metal structures 305 may be created directly onthe PCB by placing a patterned layer of copper at the junction on theopposite side of the PCB from the antenna trace. In some embodiments,the backside metal structures 305 may overlap exactly one half of thelength of the trace of the first array element of the antenna array. Asin the dual-channel antenna described above, a ground plane 302 may alsobe provided on the rear side of the PCB in the region of the radioconnector 304.

To properly fit and operate the dual-channel antenna within the sidemirror of a vehicle, a custom antenna housing designed to fit within themirror housing may be employed. To fit within the tall vertical housingtypical of truck mirrors, a vertically oriented custom antenna housingmay be used. FIG. 4 illustrates an exemplary antenna assembly 400according to an embodiment. As shown in FIG. 4, the antenna board havingthe two antenna arrays 401, 402 is placed in a housing 405 fabricatedusing circular plastic tubing, and the tubing is sealed at each end withsealant 407, 408. The sealant 407, 408 is used to keep the antenna boardin place and to make the antenna water and weather resistant. The wirefeeds from the radio connectors 403, 404, which include grounding foreach antenna array, is attached to the respective antenna array 401, 402in the center where a small hole 410 in the housing 405 allows the wiresthrough. An adhesive 406 or other connection mechanism may be applied tothe outside of the housing 405 to mount the dual-channel antenna andhousing within a side mirror of a truck.

FIG. 5 illustrates another exemplary antenna housing according to anembodiment. As shown in FIG. 5, the dual-channel antenna board 501 withtwo antenna arrays is placed on a flat piece of plastic that makes upone half of a plastic housing 502. Each of the radio connectors 503,504, which may be provided using a coaxial cable and may includegrounding for each antenna array, is attached to the respective antennaarray near the center of the dual-channel antenna board 501. Two or moresmall holes are used to thread the wire carrying radio feeds from thedual-channel antenna 501 out of the plastic housing 502. Then a similarpiece of plastic housing 505 is placed on top of the first piece 502 andthe dual-channel antenna 501, sandwiching the dual-channel antenna 501between the two pieces of plastic housing 502 and 505. The plastic ofthe plastic housing 502, 505 may be acrylic, acrylonitrile butadienestyrene (ABS), or any thermal plastic. According to an embodiment, thetwo pieces of plastic forming the plastic housing 502, 505 may besnapped together. According to an embodiment, the two pieces of plastichousing 502 are sealed on all sides to make the antenna assembly weatherresistant. The sealed antenna assembly may be mounted within a sidemirror of a vehicle. According to an embodiment, the total thickness ofthe antenna and antenna housing will be less than 6.5 mm.

FIG. 6A illustrates another exemplary antenna housing according to anembodiment. As shown in FIG. 6A, the dual-channel antenna comprises twoantenna arrays 610, 650. The antenna arrays 610, 650 are arranged on asingle PCB 612 that is placed on a flat piece of plastic 620 a thatmakes up one part of a plastic housing. Each of the radio connectors604, 654, which may be provided via a coaxial cable that includegrounding for each antenna, is attached to the respective antenna array.The distance between the two antenna arrays 610, 650 may be increased toreduce interference from reflected signals from each antenna array.

As shown in FIG. 6A, the plastic housing 620 a contains two protrusions626 for the radio connectors 604, 654. According to an embodiment, thetwo protrusions 626 may have a slight indentation to indicate placementof the radio connectors 604, 654, as well as providing stress relief forthe connector cables. For example, according to an embodiment, theprotrusions may cover approximately 11 mm of cable.

A similar piece of plastic housing 620 b is placed on top of the firstpiece 620 a and the dual-channel antenna, sandwiching the dual-channelantenna between the two pieces of plastic housing 620 a and 620 b.According to an embodiment, when all pieces of the antenna assembly aretogether, the antenna assembly may be approximately 6.5 mm thick at thecables.

As shown in FIG. 6A, according to an embodiment, each piece of plastichousing 620 a, 620 b may include multiple small plastic spacers 629placed along the length of the plastic housing piece 620 a, 620 b. Thesespacers provide a small air gap (for example, approximately 0.6 mm) thatkeeps the majority of the PCB 612 separated from the plastic housing 620a, 620 b.

The pieces of the plastic housing 620 a, 620 b may be acrylic, ABS, orany thermal plastic. According to an embodiment, the plastic housingpieces 620 a, 620 b, may include plastic snaps 622 a, 622 b to fit thetwo housing pieces together. For example, on one piece of the plastichousing 620 b, the plastic snaps 622 b may consist of small protrusionswhile on the other piece of the plastic housing 620 a, the plastic snaps622 a may consist of small holes. The plastic snaps help ensure properalignment and stability of the two plastic housing pieces 620 a, 620 bwhen placed together.

Each of the plastic housing pieces 620 a, 620 b and PCB 612 may have ahole 621 a, 621 b in the middle. When the holes 621 a, 621 b in theplastic housing 620 a, 620 b and PCB 612 are aligned, an automotiverivet may be placed through all three components and inserted into amirror casing of the vehicle's side mirror to mount to install thetransceiver antenna.

FIG. 6B illustrates a three-dimensional view of an exemplary antennahousing according to an embodiment. As shown in FIG. 6B, thedual-channel antenna comprises two antenna arrays 660, 680. The antennaarrays 660, 680 are arranged on a single PCB 662 that is placed on aflat piece of plastic 635 b that makes up one half of a plastic housing.The distance 670 between the radio connectors 664, 684 for the twoantenna arrays 660, 680 may be increased to reduce interference fromreflected signals from each antenna array.

As shown in FIG. 6B, the plastic housing piece 630 b contains twoprotrusions 669 b, 689 b for radio connectors 664, 684. According to anembodiment, the two protrusions 669 b, 689 b may have a slightindentation to indicate placement of and to hold in place the radioconnectors and to provide stress relief. A similar piece of plastichousing 635 a is placed on top of the first piece 635 b and the PCB 662,sandwiching the dual-channel antenna between the two pieces of plastichousing 635 a, 635 b.

The pieces of the plastic housing 630 a, 630 b may be acrylic, ABS, orany thermal plastic. According to an embodiment, the plastic housingpieces 630 a, 630 b, may include plastic snaps 632 a, 632 b to fit thetwo housing pieces together. For example, on one piece of the plastichousing 630 b, the plastic snaps 632 b may consist of small protrusions,while on the other piece of the plastic housing 630 a, the plastic snaps632 a may consist of small holes. The plastic snaps help ensure properalignment and stability of the two plastic housing pieces 630 a, 630 bwhen placed together.

Each of the plastic housing pieces 630 a, 630 b and PCB 662 may have ahole in the middle 636 a, 636 b, 666, respectively. When the holes 636a, 636 b, 666 in each the plastic housing pieces 630 a, 630 b and thePCB 662 are aligned, an automotive rivet 696 may be placed through allthree components and also inserted into a mirror casing of theautomobile's side mirror to mount and install the antenna assembly.Similar rivets 695, 697 may be placed through the plastic piecesrespectively through holes 635 a, 635 b at the top and holes 637 a, 637b at the bottom of the antenna housing.

An antenna housing containing a transceiver antenna may then mountedinside each side mirror of a vehicle for use in a V2V communicationsystem. FIG. 7 illustrates a vehicle side mirror 700 with an exemplarytransceiver antenna assembly 707 mounted inside according to anembodiment. In an embodiment, the transceiver antenna comprises adual-channel antenna, however, in some embodiments, the transceiverantenna may comprise a single channel antenna. As shown in FIG. 7, atypical vehicle side mirror 700 includes a mirror frame 702 attached tothe body 701 (either cab or door) of the vehicle. The mirror frame 702is typically a metal frame used to mount a mirror assembly 703 on theside of the vehicle body 701. Then a mirror 704 is installed in themounted mirror assembly 703. Other components (not shown) are alsotypically mounted within the mirror casing including electrical andmechanical components for adjusting the mirror.

The transceiver antenna assembly 707 is mounted within the mirror andpositioned to maximize signal reception while minimizing interferencefrom the vehicle body 701, mirror frame 702, and mirror assembly 703.Because the mirror frame 702 and mirror 704 are typically made of metaland will interfere with signal transmission and reception, thetransceiver antenna assembly 707 should be mounted away from the mirrorframe 702 and mirror 704 if possible. FIG. 7 illustrates exemplarydesirable region zone B 706 and undesirable region zone A 705 within themirror assembly 703 to mount the transceiver antenna assembly 707.

The connectors to ground and to radio may then be fed through aconnection between the mirror 704 and the vehicle body 701. According toan embodiment, the connectors are fed in the same path as theconnections for the rest of the mechanics and electronics operatingwithin the mirror assembly 703. Then the transceiver antenna attachmentsare connected to a radio device within the cab of the vehicle thatprocesses the received signals and creates signals for transmission.

FIGS. 8A and 8B illustrates an exemplary transceiver antenna assembly801 installed in a truck side mirror 800 attached to a truck cab 802using two mirror assembly supports 815. FIG. 8A presents a view of amirror assembly 803 as seen from the front of the truck with the casingremoved, and FIG. 8B shows a top view of the same mirror assembly withthe casing 810 attached. In FIGS. 8A and 8B, an antenna assembly 801comprising the transceiver antenna 801 is mounted on the back of themirror assembly 803, behind the other mirror electronics and mirroradjusters 808, 809, and positioned to maximize signal reception whileminimizing interference from the truck cab 802, mirror assembly 803,mirror 804, mirror mounts 805, and mirror adjusters 808, 809. Theantenna assembly 801 may have some flexibility for ease of installation.One or more automotive rivets 806 may be used to mount the antennaassembly to the mirror housing.

According to an embodiment, an RF reflective material, such as a pieceof reflective tape, i.e. a tape with a metallic film on one side, (notshown), may be placed between the antenna assembly 801 and the truck cab802. This reflective material may limit the interference from signalsreflected off the truck cab 802 received at the antenna assembly 801. Inan embodiment, the reflective material may be approximately the samelength as the PCB of the antenna assembly 801 and may optimally beplaced 20-30 mm away from the antenna assembly 801. To achieve thisspacing, the antenna assembly 801 may be installed on the back oroutside of the mirror assembly 803 and the reflective material installedinside the mirror assembly 803.

The antenna assembly 801 should preferably be mounted inside the mirrorcasing 810. The antenna assembly 801 may be completely contained withinthe casing, and invisible from outside the mirror assembly 803. Themirror casing 810 is preferably made from a non-conducting material suchas plastic that therefore causes minimal RF interference. Non-conductingplastics such as polycarbonate typically have a volume conductivitysmaller than 10⁻⁶ μS/m (as compared, for example, to pure deionizedwater or dry wood, which have a volume conductivity on the order ofapproximately 5 μS/m, or steel, which has a volume conductivity ofapproximately 10⁶ S/m). Some embodiments may specify the conductivity ofthe casing material at the RF frequencies of DSRC communications insteadof using the steady state volume conductivity numbers presented above.

The connectors to ground and to radio 807 for the antenna assembly maythen be fed in the same path as the connections for the rest of themechanics and electronics operating within the mirror housing. Then thetransceiver antenna attachments are connected to a radio device withinthe cab of the truck cab 802 that processes the received signals andcreates signals for transmission.

According to an embodiment, two channels may be used to transmit vehicledata and/or A/V data between vehicles. Two channels are desirable forredundancy and signal diversity, especially for vehicle data. Eachantenna array may transmit on one of the same two channels between thetrucks. For example, a dual-channel antenna in the driver's side mirrormay transmit and receive data over two channels, one dedicated for eachantenna in the dual-channel antenna. Then, a dual-channel antenna in thepassenger's side mirror may transmit and receive data over the same twochannels, one dedicated for each antenna in the dual-channel antenna.Data transmitted between antennas may be encrypted and signed accordingto any known encryption and verification method. Such encryption andverification ensures the fidelity of the received messages.

According to an embodiment, the transceiver antenna assemblies describedherein may be used to assist with the platooning of large trucks. Asdescribed herein, the transceiver antenna may be used in conjunctionwith a semi-autonomous vehicle convoying system to provide a safe andefficient system for convoying or platooning. Elements of active vehiclemonitoring and control in combination with the communication techniquesdescribed herein permit drivers of both a lead and a following vehicleto have a clear understanding of their environment and road conditions,including with a variety of visual displays, while offering increasedconvenience for automatic driving control.

Assisted platooning of large trucks enables the trucks to followclosely, or platoon, behind each other to reduce drag related fuel costsin a convenient and safe manner. Platooning trucks may move within a fewfeet of each other, for example with a gap between them anywhere from 10feet to 200 feet. Initial communications, however, may be exchanged whentwo trucks are up to 500 feet apart. When two or more trucks are inclose proximity, they may rapidly and continually exchangeenvironmental, control, video, or other information, thereby effectivelyestablishing a link between the trucks in order to aid with establishingand maintaining effective platooning. Communications shared betweentrucks in the short or medium distance of the platooning range mayimprove situational awareness as well as detection and monitoring ofneighboring vehicles.

According to an embodiment, once two trucks have been identified forplatooning, information may be exchanged between the two trucks toeffectuate close following. For example, the lead truck may providecontrol information such as current speed, relative distance to theother truck, braking application and/or pressure, engine or drivetraintorque, system faults, accelerometer data, tire pressure, informationabout obstacles or other vehicles detected in front of the lead truck,etc. to the other platooning trucks. When this information issuccessfully shared with another truck, the information can be passed tothe driver to encourage the driver to act, such as by speeding up orslowing down. Alternatively, a system within the truck may be engaged toautomatically control the acceleration and braking of the followingtruck based on the information received from another truck.

According to an embodiment, a following truck may receive specificdirections, rather than merely useful data, from a lead truck, and canimplement those directions at the following truck for effectiveplatooning. For example, if the front truck begins braking, the brakingsignal information may be transmitted immediately from the front truckas vehicle information via DSRC to the following truck, which can beginbraking in synchrony with the front truck. Similarly, the lead truck maybe encouraged to speed up or slow down based on similar informationreceived from the following truck. Therefore, each truck may be aware ofthe state of all of the other platooning trucks.

A dual-channel antenna may receive information on both channels andconvey the received information to a radio or receiver. The receivedinformation may then be processed by a processor located within the cabof the truck. Such processing may include the parsing of differentinformation types and the determination of how the information should beused.

In the event of a loss of signal between the antennas of platooningtrucks, certain safety precautions may be implemented. For example, thetrailing vehicles may be instructed to immediately start slowing so thatif the lead truck begins braking while the connection is lost, a safegap between the trucks can still be maintained.

According to an embodiment, platooning trucks may also exchange AN data.For example, the two drivers may communicate with each other using anaudio link provided between the two trucks. This has some advantage overCitizen's Band (CB) broadcast radio communications, in that the DSRCcommunication may be set up to be encrypted and decrypted only betweenthe two vehicles, providing privacy for the communication. In someembodiments, the following truck may receive video from a camera placedin the lead truck. In some instances, only the following truck mayreceive video data, while in other instances, the lead truck may receivevideo data from the following truck.

For example, the video data may be displayed on a screen or userinterface within the truck. Traditionally the driver of a followingtruck sees primarily the back of the lead truck and some small amount ofspace to each side of the lead truck. However, according to anembodiment, a display may be provided to the driver of the followingtruck that shows video data captured by a forward-looking camera in thelead truck. This display will then provide the driver of the followingtruck an unobstructed view of what is ahead of the pair of trucks. Thedriver of the following truck may then have similar knowledge of theroad ahead as the driver of the lead truck and may operate the followingtruck accordingly. For example, the driver of the following truck mayobserve and react to unexpected developments that otherwise may not havebeen seen, such as road hazards, wild animals at the side of thehighway, traffic conditions, etc.

The screen or other user interface may be visor or dash mounted, or inany other convenient location visible to the driver. The A/V data mayalso be used to detect and prevent drifting within or out of the roadlane, for example, by calculating any drift or offset with the laneguides for the lead truck or with the tail end of a leading truck for afollowing truck. Upon detection of a drift or offset, a notification oralert may be sent to the driver of the drifting vehicle and correctiveaction taken.

According to an embodiment, multiple trucks may be linked forplatooning. For example, safe platoons of three or more trucks may beinitiated where the middle truck acts as both a lead truck (to therear-most truck) and a following truck (to the lead truck). Then themiddle truck may transmit and receive information from both of the othertrucks.

According to an embodiment, additional vehicles may communicate with theplatooning trucks. For example, passenger vehicles or light trucks mayestablish communication with one or more trucks via the dual-channelantenna described herein.

Looking at FIG. 8, it can be appreciated that side mirrors that arelarge enough, and protrude far enough out from a truck cab, to providesufficient visibility for large and long tractor-trailers, also willprovide significant wind resistance, and therefore drag, therebydecreasing gas mileage. To provide an equivalent rear-looking view alongthe sides of a vehicle, it is possible to provide video cameras indifferent locations around a tractor-trailer, with one or more viewscreens in the cab. Such cameras are typically much smaller thanmirrors, will not need to protrude as far as side mirrors do, and willtherefore will provide less drag.

FIGS. 9A and 9B illustrate rear view assemblies for vehicles using avideo camera mounted to the side of a vehicle. In FIG. 9A, a side viewassembly 903 is mounted to a vehicle body 902 or side door with a sideview assembly support 915. The side view assembly 903 comprises a camera904 for viewing back along the side of the vehicle, and also comprises atransceiver antenna assembly 901 contained within the side view assembly903 and invisible from the outside of the side view assembly 903. InFIG. 9B, a side view assembly 913 is mounted to a vehicle body 902 orside door with a side view assembly support 925. The side view assembly913 comprises a camera 904 for viewing back along the side of thevehicle, and also comprises an antenna assembly 911 mounted to theoutside of the side view assembly 913. Antenna array placement within orattached to one or more casings for smaller side-mounted rear-viewingassemblies comprising cameras may preserve line-of-sight forcommunication between a lead vehicle and a following vehicle, whilepresenting a smaller wind drag than encountered with larger side viewmirror assemblies.

While the invention has been described in detail above with reference tosome embodiments, variations within the scope and spirit of theinvention will be apparent to those of ordinary skill in the art. Thus,the invention should be considered as limited only by the scope of theappended claims.

1. A system for communicating between a plurality of vehicles, eachvehicle having at least one side mirror, the system comprising: in eachvehicle: at least one dual-channel antenna, mounted in a respective sidemirror, and an antenna housing for mounting the at least onedual-channel antenna in the respective side mirror; and the systemfurther comprising, in each vehicle: a radio connected to the at leastone dual-channel antenna in that vehicle to manage transmission andreception of information transmitted and received via the dual-channelantennas.
 2. The system of claim 1, wherein both channels of eachdual-channel antenna carry vehicle data.
 3. The system of claim 1,wherein a single channel of each dual-channel antenna carriesaudio/video data.
 4. The system of claim 1, wherein each dual-channelantenna is implemented on a single printed circuit board.
 5. The systemof claim 1, wherein the at least one dual-channel antenna comprises afirst antenna and a second antenna, wherein the first antenna and thesecond antenna are aligned in a collinear direction along a common axisof orientation.
 6. The system of claim 1, wherein each vehicle has atleast two side mirrors, and each respective side mirror in each vehiclehas at least one dual-channel antenna.
 7. The system of claim 1, whereinthe radio operates in a Dedicated Short Range Communications (DSRC)band.
 8. The system of claim 1, wherein each vehicle is a truck.
 9. Atwo-way communication method among two or more vehicles, each of the twoor more vehicles having two side mirrors, the method comprising:communicating information between a pair of said two or more vehiclesusing a transceiver antenna mounted in each side mirror of each vehiclein the pair, at least one side mirror of one of the pair of vehiclesbeing in line-of-sight communication with at least one side mirror ofthe other of the pair of vehicles; and managing communicated informationwith a radio in each vehicle, the radio connected to the transceiverantennas mounted in respective side mirrors of the respective vehicle tomanage transmission and reception of the communicated informationtransmitted and received via the transceiver antennas.
 10. The method ofclaim 9, wherein the radio operates in a Dedicated Short RangeCommunications (DSRC) band.
 11. The method of claim 9, wherein eachtransceiver antenna is a dual-channel antenna.
 12. The method of claim11, further comprising communicating vehicle data over both channels ofeach transceiver antenna.
 13. The method of claim 11, further comprisingcommunicating audio/video data over a single channel of each transceiverantenna.
 14. The method of claim 9, wherein each of the two or morevehicles is a truck.
 15. A rear view assembly for a vehicle, comprising:a casing mounted on a side of the vehicle; a viewing device in anadjustable mount attached to the casing and positioned to provide arear-looking view along the side of the vehicle; and at least oneantenna assembly comprising a dual-channel antenna to transmit andreceive radio frequencies, said antenna assembly mounted to the casing.16. The rear view assembly of claim 15, wherein the casing is fabricatedfrom a material with an electrical conductivity less than 10 μS/m. 17.The rear view assembly of claim 16, wherein the antenna assembly ismounted inside the casing.
 18. The rear view assembly of claim 17,wherein the antenna assembly is not visible from the outside of the rearview assembly.
 19. The rear view assembly of claim 15, wherein theantenna assembly is mounted to the outside of the casing.
 20. The rearview assembly of claim 15, wherein the vehicle is a truck, and the rearview assembly is designed to be mounted on a side of the truck.
 21. Therear view assembly of claim 15, wherein the viewing device is a mirror.22. The rear view assembly of claim 15, wherein the viewing device is acamera.